Im a farm boy and a former railroad builder, so I have a lot of experience with a bunch of different diesels. Lets start with what I know and love the best. Ford. Ford has nearly as nice a ride as a chevy, but it is noticibly rougher then the Chevy for the reason that Chevy has the independent suspension which has been mentioned before on this thread. But even so, the Fords still have a pretty nice ride. The 7.3L didnt get a turbo put on it until mid 94, and had a mild redesign in 1999 along with the new body style. I have towed enough with a 97 Powerstroke to say it is not my first choice for a 7.3, but I would not hesitate to buy a pre 99 if the deal was good enough. The 99s and newer 7.3s respond well to simple upgrades. An air intake, 5 inch exhaust and a chip had my cousins F250 hauling nearly 30k pound trailers of steers up 6% grade hills at 75 MPH no sweat, never had to downshift or anything. Figured it had between 750-800 ft. ibs. of torque in that configuration at least. That is what spurred another of my cousins to buy his 01 7.3L F350. Now that being said, if you elect to buy an F250, be aware that the front suspension is a little funny and will give you problems, unlike the F350. a stock 7.3L at its peak made 235HP and 510 foot pounds of torque, mild when compared to what its capable of and what new diesels are making.
Onwards to the 6.0L Powerstroke. I know guys who have had great luck with them, and guys who swear to stay away. I almost bought an 04 with 200k miles on it, but the price, well, we just couldnt agree. anyway, the same cousin who had the 7.3L F250 sold it for a newer 06 F350 with the 6.0L. According to my research, and his, the vast majority of the issues with the 6.0L were ironed out towards the middle of the 04 model year. The 06 of my cousins never got that message. That thing was in the shop almost every week, and when it wasnt, it was.
Possibly a lemon, it happens. On the railroad we had an 05 F550 with the 6.0L, and that thing had the snot pulled out of it, never skipped a beat until about 150k mile mark. not all that durable of a platform when compared to the older 7.3L. Now I have it on good athority by another guy i know who has a 6.0L with 250k miles on it that if you mod the engine right, it can be real durable, this is also known in the 6.0L world as bulletproofing. The injectors will fail, no question, and when they do, replace them with an aftermarket set (and a bigger set if you want) for less cost then you can from Ford and theyl last a whole lot longer. Also, removal of the DPF and other emissions equipment is essential to making this engine last. And one thing almost forgot to put in here but is just as essential to these engines longevity is to get some strong head studs put in them, that is another must. With that, they can last longer and have more power for fun or work. You have been warned and informed haha. These made 325 claimed HP and 560 foot pounds at the onset and in 05 were pushed to a whopping, wait for it, 570 foot pounds of torque! wow! big increase there haha.
The 6.4L Powerstroke...I honestly love this engine. I have driven a few for work and they are powerhouses. While towing with an F350 on the railroad and working them like mad, they just asked for more. Youl hear a few horror stories I'm sure, but every engine has their lemons. It happens, but the ones I have experiance with never once missed a beat. However, with an unmodded 7.3L and 6.0L youl get halfway decent fuel economy and better when their modded. stock we usually saw between 16-18 with the 7.3L and about that with the 6.0L, not towing. modded can get those number even higher. the 6.4L, with all the emissions crap, youl be LUCKY to crack the 14 mark. removal of the emissions garbage (which technically is illegal, so all i can say is thank God I live in South Dakota, where Im still free haha) will see fuel economy jump to nearly 20-22 mpg. All new diesels now get crap mileage because of the emissions garbage, so be aware of that. Some tweaking will rectify that for you tho. most of these are bulletproof, but the damage from the 6.0L was done as far as Fords and Internationals relationship goes. Also bad publicity always travels far and wide, whereas good publicity and song of praise like what I sing of the 6.4L typically does not. You really do need to get rid of the emissions stuff tho if you are able to, because they litterally choke these engines to death in the long run, and with the emissions stuff in tact, youl be lucky to get up to a measly 300k miles, and i mean extremely lucky. An easy feat for a 7.3L. I would not hesitate to buy one of these tho (actually im thinking about selling my car and using that to help buy a nice king ranch F350 with the 6.4L). Either that or a Laramie Longhorn Ram 3500, but we'll get to that in due time haha. but Im also torn as to weather or not i want to buy a clean 7.3L too, but thats my delema and not relevant right now haha.
The 6.7L Powerstroke. My cousin with the supped up 7.3L and problemsome 6.0L decided to skip the 6.4L (his loss) and go straight for a brand new 2012 F350 with the 6.7L in their release they had 390 HP and 735 foot pounds of torque, then about mid 2011 as an answer to the new 6.7L Cummins, they bumped it up to a staggering 400HP and 800 foot pounds. The new Cummins and Powerstroke each have the same torque numbers, but the Powerstroke has an additional 50 HP and the benefit of 2 more cylinders. For those 2 reasons the Powerstroke is able to maintain its power up a steep grade easier then the new Cummins can. Even with a 25k pound fifth wheel behind it, it will still throw you back in your seat if you give it a little gas. its truly phenomenal. So far, Ted has no reported issues with it and loves it to death. But the fuel economy still suffers as compared to older diesels. I would assume the emissions control stuff on these is probably about as good for the engines as what it is on the 6.4L, but I cant say for sure, only time will tell. I think that about covers the Powerstrokes for you.
The Duramax/Allison combo.
Great combo really. Displacement has always remained at 6.6L (400 CI) but there are a couple of iterations of it. the first Duramax debuted in 2001 as the LB7. This version made 235HP (same as the peak 7.3L Powerstroke figures) and made 500 ft pounds of torque, until 2004. The LB7 was pushed to 300 HP (one year only for that power with the LB7) and 520 foot pounds of torque. Pretty good engine, but as the first iteration it has its fair share of problems. injector issues and overheating is typically where the problems arise on this version, GM denied it at first but law suits made them extend their warranties and they had to do a few recalls. in late 2004 (like the last 1/4 of the year) came out the LLY version. 310 horsepower and 520 foot pounds. The LLY resolved most of the overheating and injector issues, and made a bit more power as demonstrated above. both of these engines I and my pals have had success with, they get awesome fuel economy (like 22ish, which puts the 7.3L and 6.0L to shame). Then in mid 2006 the LBZ came out. 360 HP and 650 foot pounds (same torque as the 6.4L Powerstroke, 10 more HP) Also, for as long as the LLY was available in 2006 power was bumped up to 605 foot pounds. The LLY was one of the least emissions controlled Duramax engines, which is why its my main choice for the platform, if your going to keep stock. As far as I know the LBZ lost a little in way of fuel economy, but im not certain on that point. Anyway, the Duramax was revised again in mid 2007 as the LMM version, not a huge increase in power, but a few internal parts were modified for strength and such. The LMM made 365hp, but it delivered it at a 100 RPMs lower then before. Torque numbers increased to a whopping 660 foot pounds. it remained this way until 2011, when it was replaced again by the LML, that version supposedly makes 397 hp and 765 pound feet of torque, but honestly, dyno numbers suggest it makes less then that. When compared to a 800 claimed foot pound of torque 6.7L Powerstroke on the same dyno, the Ford put down a whopping 745 foot pounds to the ground. the Duramax on the other hand only managed to put down 665 foot pounds to the ground, which makes me think the numbers have been fudged. or maybe the drivetrain in the Chevy is highly inefficient. either way, I wouldnt pay the premium for the new Duramax. wait and buy used (but thats always been my philosophy haha). As far as reliability and issues with the newer Duramax, the only ones I can really attest to are the LLY, the LB7 and the LLM, those are pretty reliable platforms, but they dont like to be too loaded up with weight behind them, they will struggle a bit more then what a similar Powerstroke would. Hope that helps as far as the Duramax is concerned, but if your planing on having like a boat or some toys behind it, it will work. I know a guy who just towed a big fifth wheel camper and a big boat behind that with his 2500 LBZ Duramax, he said it was able to handle it but it didnt like the hills very much, as was expected. The rear suspension looked like it was coping with the weight really well tho when i saw him towing it all down the road, so its got that going for it for sure.
Now, Cummins...the 5.9L is nearly indestructible, but there are timelines available for its power output that will be of much use. I know for a fact in 2006 the 5.9L made 325HP and 610 foot pounds since i was considering buying one of that vintage. the 6.7L is almost identical to the 5.9L, same block I believe too, and Ive done a lot of towing with both. Good, reliable platform, but like i mentioned earlier, I think the addition of 2 more cylinders would do a world of good for this platform, even keeping it inline would work. But the new 6.7L is a monster of an engine, and I would buy one in a heartbeat if i could find a decent deal. I think Im gunna wait until the 2011s are a tad bit older, cuz I really want a 6.7L mega cab Laramie Longhorn 3500 shortbox dually...like bad. I think I would prefer this over the twin turbo 6.4L King Ranch F350, and I honestly never thought Id say that, especially about a Dodge. Be forewarned tho, older dodges are not built very well and have a lot of creaks and moans and rattles etc. I hope the tradition of crap bodies has come to an end with this new body style they have, cuz I really want it to be a good truck. They tow like mad even with the 6 cylinders (which a lot of people prefer) and the Cummins is legendary. fuel economy isnt the best, and the ride is the worst of the bunch traditionally but i cant say that about the newest ones since I havnt been in anything newer then an 08 Cummins 3500 crew cab longbed, but it was a at the time top end Laramie and its suspension was very very stiff, made me wish I was riding in the F350 Lariat or the 2500 Chevy LTZ we had. But strong engine, but be aware, its still a Dodge tranny behind that engine, which have always been crap. I hope the newer ones are better, but for older ones, if they have done a lot of towing, expect the tranny behind the Cummins to go out at around 150kish miles. some have been luckier then others tho. thats my 2 cents anyway, hope this helps you in your decision.
Now all of that being said, remember that the 6.4L and 6.7L Powerstrokes require cab removal for top end work on them, so thats another thing to consider. If its under warranty it wont matter as much, but if your without a warranty and they have to remove the cab to do some work to your diesel, its about a 20 hour plus job, so it will be a major pain to pay for unless its something you think you could do yourself (and I wouldnt recommend that haha). The 6.7L Cummins, 5.9L Cummins, all Duramax's and the 6.0L and 7.3L do not require cab removal for top end work, but i think youd find it easier sometimes haha, some of those engines are really jammed in there tight.
